Abstract: Microstructurally short cracks with lengths up to about ten grains are known to be strongly influenced by the microstructural features in the neighborhood of the crack tip. These include randomly shaped and oriented crystal grains and strongly orientation dependent deformation behavior of the grains. The goal of our work is to propose computational models aiming to quantify the effects of random grain orientations on the variability of crack tip opening and sliding displacements (CTOD, CTSD).A Voronoi tessellation based computational model has been developed to simulate the random grain structure. The constitutive behavior of individual grains includes randomly oriented anisotropic elasticity and crystal plasticity (where Schmid resolved stress is taken into account). The equilibrium equations are solved with macroscopicboundary conditions at the scale of the component using commercially available finite element solver ABAQUS.